Java Spring @Scheduled tasks executing twice

Question

I have a simple test method here that is set to run every 5 seconds and it does, but looking at the System.out you can see it appears to be doing something odd.

Answer 1

I had the same problem. I was using annotation based configuration as follows:

@Configuration
@EnableScheduling
public class SchedulerConfig {

    @Scheduled(fixedDelay = 60 * 1000)
    public void scheduledJob() { 
        // this method gets called twice... 
    }   
}

I was also extending AbstractAnnotationConfigDispatcherServletInitializer for initializing the same.

public class SpringWebApplicationInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

@Override
protected Class[] getRootConfigClasses() {
    return new Class[] { MainConfig.class, SchedulerConfig.class };
}

@Override
protected Class[] getServletConfigClasses() {
    return new Class[] {SpringWebConfig.class};
}

@Override
protected String[] getServletMappings() {
    return new String[] { "/" };
}

@Override
protected Filter[] getServletFilters() {
    final CharacterEncodingFilter encodingFilter = new CharacterEncodingFilter();
    encodingFilter.setEncoding(CHARACTER_ENCODING);
    encodingFilter.setForceEncoding(true);
    return new Filter[] { encodingFilter };
}

}

Removing the SchedulerConfig.class from getRootConfigClasses() method did the trick for me.

@Override
protected Class[] getRootConfigClasses() {
    return new Class[] { MainConfig.class };
}

I hope this helps.